#include <stdio.h>
#include <stdlib.h>
#include <iostream>

using namespace std;
unsigned long long d=1;

int main(int argc, char *argv[])
{
	int a=atoi(argv[1]);
	for (int i=1; i<=a; i++)
		d*=i;
	if (d>14446744073709551615)
		cout<<"too much!"<<endl;
	cout<<d<<endl;
	return 0;
}

